The public beta can be downloaded from Microsoft's website, although you'll need a spare USB flash drive or writable DVD to install it. The Windows 8 consumer preview features Metro-style applications and over 100,000 changes to the developer preview released last year.

UPDATE: Microsoft has just announced a nice bonus – all apps in the Windows 8 app store will be free to download when using the consumer preview. New apps will be added from now on but it's all subject change – so you might as well go on a download spree as soon as you've got the new OS up and running.